The present invention relates to mounting structures, and particularly mounting structures which allow freedom of pivoting movement which can be hand-controlled and positioned at a desired orientation. Such mounting structures find particular applications in vehicles for mounting rear view mirrors or electronic screen devices to the vehicle, for ready hand positioning by the driver or passenger to a different orientation for viewing.
Numerous situations exist where devices are mounted so as to be hand positionable about a pivot point 12. One common situation is in a vehicle. The driver of the vehicle typically has at least one, and more commonly several, rear view mirrors. Because drivers differ in height and driving body positioning and may differ in what area they exactly wish to see in the rear view mirror, the rear view mirrors commonly include a ball-and-socket type of friction hinge to allow angular repositioning of the mirror. Other screen devices, such as GPS devices, PDA devices, etc., are also commonly mounted to a dashboard of the vehicle on a ball-and-socket type of friction hinge. The term “friction hinge”, as used herein, denotes that the hinge is not free swinging but rather involves a friction force which ordinarily keeps the hinge angle from moving, but which friction force can be overcome by hand pressure when the user desires to position the supported item (electrical component or mirror) at a different angular position.
Such friction hinges have a variety of design constraints and goals. They must be sturdy and robust, to support the weight of the mirror or other device being supported and to withstand not only the forces of repeated repositionings, but also substantially larger forces which may occur when the device is inadvertently bumped (such as when loading something into the vehicle). They must be able to provide the correct amount of friction force so as not to be too “tight” or too “loose” for hand positioning, while not slipping during vibration such as when the vehicle is travelling over bumpy roads. The friction hinge structures must be able to retain their ease of functionality over years or decades of use. Further, particularly because vehicle interiors can be subject to tremendous temperature swings, such as temperature differences in excess of 100° F. between winter and summer use, the friction force must remain relatively constant over a very wide temperature range. The mounts should also be low in cost. They should be easy to assemble, either in manufacture of the vehicle or later when adding an aftermarket mirror or device to the vehicle.
Many ball-and-socket joints include a socket which is either finally assembled or formed only after the ball is in place. Obviously, the final assembly or formation adds a manufacturing or assembly step which would preferably be avoided. Further, many ball-and-socket joints do not permit disassembly, which would be beneficial particularly in instances when the device being held is also used outside the vehicle, or is frequently replaced.
Another style of ball-and-socket friction hinge can be assembled quickly and easily by snapping the ball into the socket after the socket has been fully assembled or formed. To facilitate such snap assembly, often either the socket or ball (or both) is made up of multiple different portions or arms which can bend or move relative to one another. A prior art example of such a mounting or snap assembly friction hinge is shown in U.S. Pat. No. 7,296,771, incorporated by reference, and the present invention is particularly contemplated as an improvement over the type of snap assembly friction hinge taught in U.S. Pat. No. 7,296,771. The movement of the arms causes a bending stress point which can deteriorate or break, leading to a failure of the joint. Better methods and structures of friction hinges are needed.